1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "java_lang_Thread.h"
18
19 #include "common_throws.h"
20 #include "jni/jni_internal.h"
21 #include "mirror/object.h"
22 #include "monitor.h"
23 #include "native_util.h"
24 #include "nativehelper/jni_macros.h"
25 #include "nativehelper/scoped_utf_chars.h"
26 #include "scoped_fast_native_object_access-inl.h"
27 #include "scoped_thread_state_change-inl.h"
28 #include "thread.h"
29 #include "thread_list.h"
30 #include "verify_object.h"
31
32 namespace art {
33
Thread_currentThread(JNIEnv * env,jclass)34 static jobject Thread_currentThread(JNIEnv* env, jclass) {
35 ScopedFastNativeObjectAccess soa(env);
36 return soa.AddLocalReference<jobject>(soa.Self()->GetPeer());
37 }
38
Thread_interrupted(JNIEnv * env,jclass)39 static jboolean Thread_interrupted(JNIEnv* env, jclass) {
40 return static_cast<JNIEnvExt*>(env)->GetSelf()->Interrupted() ? JNI_TRUE : JNI_FALSE;
41 }
42
Thread_isInterrupted(JNIEnv * env,jobject java_thread)43 static jboolean Thread_isInterrupted(JNIEnv* env, jobject java_thread) {
44 ScopedFastNativeObjectAccess soa(env);
45 MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
46 Thread* thread = Thread::FromManagedThread(soa, java_thread);
47 return (thread != nullptr) ? thread->IsInterrupted() : JNI_FALSE;
48 }
49
Thread_nativeCreate(JNIEnv * env,jclass,jobject java_thread,jlong stack_size,jboolean daemon)50 static void Thread_nativeCreate(JNIEnv* env, jclass, jobject java_thread, jlong stack_size,
51 jboolean daemon) {
52 // There are sections in the zygote that forbid thread creation.
53 Runtime* runtime = Runtime::Current();
54 if (runtime->IsZygote() && runtime->IsZygoteNoThreadSection()) {
55 jclass internal_error = env->FindClass("java/lang/InternalError");
56 CHECK(internal_error != nullptr);
57 env->ThrowNew(internal_error, "Cannot create threads in zygote");
58 return;
59 }
60
61 Thread::CreateNativeThread(env, java_thread, stack_size, daemon == JNI_TRUE);
62 }
63
Thread_nativeGetStatus(JNIEnv * env,jobject java_thread,jboolean has_been_started)64 static jint Thread_nativeGetStatus(JNIEnv* env, jobject java_thread, jboolean has_been_started) {
65 // Ordinals from Java's Thread.State.
66 const jint kJavaNew = 0;
67 const jint kJavaRunnable = 1;
68 const jint kJavaBlocked = 2;
69 const jint kJavaWaiting = 3;
70 const jint kJavaTimedWaiting = 4;
71 const jint kJavaTerminated = 5;
72
73 ScopedObjectAccess soa(env);
74 ThreadState internal_thread_state = (has_been_started ? kTerminated : kStarting);
75 MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
76 Thread* thread = Thread::FromManagedThread(soa, java_thread);
77 if (thread != nullptr) {
78 internal_thread_state = thread->GetState();
79 }
80 switch (internal_thread_state) {
81 case kTerminated: return kJavaTerminated;
82 case kRunnable: return kJavaRunnable;
83 case kTimedWaiting: return kJavaTimedWaiting;
84 case kSleeping: return kJavaTimedWaiting;
85 case kBlocked: return kJavaBlocked;
86 case kWaiting: return kJavaWaiting;
87 case kStarting: return kJavaNew;
88 case kNative: return kJavaRunnable;
89 case kWaitingForTaskProcessor: return kJavaWaiting;
90 case kWaitingForLockInflation: return kJavaWaiting;
91 case kWaitingForGcToComplete: return kJavaWaiting;
92 case kWaitingPerformingGc: return kJavaWaiting;
93 case kWaitingForCheckPointsToRun: return kJavaWaiting;
94 case kWaitingForDebuggerSend: return kJavaWaiting;
95 case kWaitingForDebuggerToAttach: return kJavaWaiting;
96 case kWaitingInMainDebuggerLoop: return kJavaWaiting;
97 case kWaitingForDebuggerSuspension: return kJavaWaiting;
98 case kWaitingForDeoptimization: return kJavaWaiting;
99 case kWaitingForGetObjectsAllocated: return kJavaWaiting;
100 case kWaitingForJniOnLoad: return kJavaWaiting;
101 case kWaitingForSignalCatcherOutput: return kJavaWaiting;
102 case kWaitingInMainSignalCatcherLoop: return kJavaWaiting;
103 case kWaitingForMethodTracingStart: return kJavaWaiting;
104 case kWaitingForVisitObjects: return kJavaWaiting;
105 case kWaitingWeakGcRootRead: return kJavaRunnable;
106 case kWaitingForGcThreadFlip: return kJavaWaiting;
107 case kNativeForAbort: return kJavaWaiting;
108 case kSuspended: return kJavaRunnable;
109 // Don't add a 'default' here so the compiler can spot incompatible enum changes.
110 }
111 LOG(ERROR) << "Unexpected thread state: " << internal_thread_state;
112 return -1; // Unreachable.
113 }
114
Thread_holdsLock(JNIEnv * env,jclass,jobject java_object)115 static jboolean Thread_holdsLock(JNIEnv* env, jclass, jobject java_object) {
116 ScopedObjectAccess soa(env);
117 ObjPtr<mirror::Object> object = soa.Decode<mirror::Object>(java_object);
118 if (object == nullptr) {
119 ThrowNullPointerException("object == null");
120 return JNI_FALSE;
121 }
122 Thread* thread = soa.Self();
123 return thread->HoldsLock(object);
124 }
125
Thread_interrupt0(JNIEnv * env,jobject java_thread)126 static void Thread_interrupt0(JNIEnv* env, jobject java_thread) {
127 ScopedFastNativeObjectAccess soa(env);
128 MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
129 Thread* thread = Thread::FromManagedThread(soa, java_thread);
130 if (thread != nullptr) {
131 thread->Interrupt(soa.Self());
132 }
133 }
134
Thread_setNativeName(JNIEnv * env,jobject peer,jstring java_name)135 static void Thread_setNativeName(JNIEnv* env, jobject peer, jstring java_name) {
136 ScopedUtfChars name(env, java_name);
137 {
138 ScopedObjectAccess soa(env);
139 if (soa.Decode<mirror::Object>(peer) == soa.Self()->GetPeer()) {
140 soa.Self()->SetThreadName(name.c_str());
141 return;
142 }
143 }
144 // Suspend thread to avoid it from killing itself while we set its name. We don't just hold the
145 // thread list lock to avoid this, as setting the thread name causes mutator to lock/unlock
146 // in the DDMS send code.
147 ThreadList* thread_list = Runtime::Current()->GetThreadList();
148 bool timed_out;
149 // Take suspend thread lock to avoid races with threads trying to suspend this one.
150 Thread* thread = thread_list->SuspendThreadByPeer(peer,
151 /* request_suspension= */ true,
152 SuspendReason::kInternal,
153 &timed_out);
154 if (thread != nullptr) {
155 {
156 ScopedObjectAccess soa(env);
157 thread->SetThreadName(name.c_str());
158 }
159 bool resumed = thread_list->Resume(thread, SuspendReason::kInternal);
160 DCHECK(resumed);
161 } else if (timed_out) {
162 LOG(ERROR) << "Trying to set thread name to '" << name.c_str() << "' failed as the thread "
163 "failed to suspend within a generous timeout.";
164 }
165 }
166
167 /*
168 * Alter the priority of the specified thread. "new_priority" will range
169 * from Thread.MIN_PRIORITY to Thread.MAX_PRIORITY (1-10), with "normal"
170 * threads at Thread.NORM_PRIORITY (5).
171 */
Thread_setPriority0(JNIEnv * env,jobject java_thread,jint new_priority)172 static void Thread_setPriority0(JNIEnv* env, jobject java_thread, jint new_priority) {
173 ScopedObjectAccess soa(env);
174 MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
175 Thread* thread = Thread::FromManagedThread(soa, java_thread);
176 if (thread != nullptr) {
177 thread->SetNativePriority(new_priority);
178 }
179 }
180
Thread_sleep(JNIEnv * env,jclass,jobject java_lock,jlong ms,jint ns)181 static void Thread_sleep(JNIEnv* env, jclass, jobject java_lock, jlong ms, jint ns) {
182 ScopedFastNativeObjectAccess soa(env);
183 ObjPtr<mirror::Object> lock = soa.Decode<mirror::Object>(java_lock);
184 Monitor::Wait(Thread::Current(), lock.Ptr(), ms, ns, true, kSleeping);
185 }
186
187 /*
188 * Causes the thread to temporarily pause and allow other threads to execute.
189 *
190 * The exact behavior is poorly defined. Some discussion here:
191 * http://www.cs.umd.edu/~pugh/java/memoryModel/archive/0944.html
192 */
Thread_yield(JNIEnv *,jobject)193 static void Thread_yield(JNIEnv*, jobject) {
194 sched_yield();
195 }
196
197 static JNINativeMethod gMethods[] = {
198 FAST_NATIVE_METHOD(Thread, currentThread, "()Ljava/lang/Thread;"),
199 FAST_NATIVE_METHOD(Thread, interrupted, "()Z"),
200 FAST_NATIVE_METHOD(Thread, isInterrupted, "()Z"),
201 NATIVE_METHOD(Thread, nativeCreate, "(Ljava/lang/Thread;JZ)V"),
202 NATIVE_METHOD(Thread, nativeGetStatus, "(Z)I"),
203 NATIVE_METHOD(Thread, holdsLock, "(Ljava/lang/Object;)Z"),
204 FAST_NATIVE_METHOD(Thread, interrupt0, "()V"),
205 NATIVE_METHOD(Thread, setNativeName, "(Ljava/lang/String;)V"),
206 NATIVE_METHOD(Thread, setPriority0, "(I)V"),
207 FAST_NATIVE_METHOD(Thread, sleep, "(Ljava/lang/Object;JI)V"),
208 NATIVE_METHOD(Thread, yield, "()V"),
209 };
210
register_java_lang_Thread(JNIEnv * env)211 void register_java_lang_Thread(JNIEnv* env) {
212 REGISTER_NATIVE_METHODS("java/lang/Thread");
213 }
214
215 } // namespace art
216